Medical Glossary

An unwanted or unexpected health effect occurring after taking a medication.

The most serious FDA warning, highlighting life-threatening risks in a bordered box at the top of a drug label.

A condition or situation where a medication should not be used due to potential harm.

When one substance affects the activity of a drug, potentially altering safety or effectiveness.

A secondary, typically undesirable effect of a medication beyond its intended therapeutic effect.

Another name for a Boxed Warning — the FDA's strictest warning requirement.

Ongoing monitoring of a drug's safety after it has been approved for public use.

An FDA-required safety plan for certain medications with serious safety concerns.

The biologically active component responsible for a medication's therapeutic effect.

The official medical name of a drug, distinct from its brand name.

The proprietary trademarked name given to a drug by its manufacturer.

Components of a medication that are not therapeutically active, such as binders, fillers, and coloring agents.

A medical product derived from living sources, such as vaccines, blood components, and gene therapies.

A biologic product that is highly similar to an FDA-approved reference biologic with no clinically meaningful differences.

A medication created to be the same as an existing approved brand-name drug in dosage form, safety, strength, and route of administration.

A medication available without a prescription that is safe and effective for self-medication when used as directed.

How the body processes a drug — absorption, distribution, metabolism, and excretion ("what the body does to the drug").

How a drug affects the body — its mechanism of action and biological effects ("what the drug does to the body").

The physical form of a medication, such as tablet, capsule, injection, solution, or cream.

The path by which a medication enters the body, such as oral, intravenous, topical, or inhalation.

The proportion of a drug that enters the bloodstream when introduced into the body and is available for therapeutic effect.

The time required for the concentration of a drug in the body to reduce by half.

A ratio comparing the toxic dose of a drug to its therapeutic dose — narrower index means more careful monitoring is needed.

The condition where drug intake and elimination are balanced, resulting in a stable drug concentration in the body.

An inactive substance or treatment used as a control in clinical trials to measure the actual effect of a drug.

A research study conducted with human volunteers to evaluate the safety and effectiveness of a medical intervention.

A unique 10-digit identifier for human drugs in the US, consisting of labeler, product, and package code segments.

FDA categorization of recalls: Class I (serious harm/death risk), Class II (temporary effects), Class III (unlikely to cause harm).

The entity responsible for the label on a drug product — typically the manufacturer, packer, or distributor.

An FDA document standard for exchanging drug labeling information in structured XML format.

An application for a generic drug approval, showing the product is bioequivalent to an existing approved brand-name drug.

The formal application submitted to the FDA requesting approval to market a new drug in the US.

The official FDA determination that a drug is safe and effective for its intended use based on reviewed clinical data.

The use of an FDA-approved drug for a purpose, dosage, or population not included in its approved labeling.

A drug developed to treat a rare disease affecting fewer than 200,000 people in the US, often receiving special development incentives.

Intellectual property protection granting the drug manufacturer exclusive rights to market the medication for a limited period.

The prescribed amount and frequency of a medication to be taken by the patient.

The gradual adjustment of a medication dose to achieve the optimal therapeutic effect with minimal side effects.

An initial higher dose of a medication to quickly reach a therapeutic concentration in the body.

The regular dose of a medication needed to maintain the desired therapeutic effect after the loading dose.

A Latin abbreviation (pro re nata) meaning "as needed" — medication taken only when required for symptoms.

A route of administration where the medication is placed under the tongue for absorption into the bloodstream.

A route of administration where medication is applied directly to the skin or mucous membranes.

A formulation designed to release the active ingredient slowly over an extended period, reducing dosing frequency.

The process by which normal cells transform into cancer cells, sometimes referenced in drug labeling regarding long-term risks.

The process of genetic mutation, evaluated in drug safety studies to assess potential heritable genetic damage.

Drug-related harmful effects on fetal development that can cause birth defects when taken during pregnancy.

A reduced response to a drug over time, requiring higher doses to achieve the same therapeutic effect.

A physical or psychological state where the body adapts to a drug and requires it to function normally.

Symptoms that occur when a person stops or reduces use of a medication they have become physical dependent on.

A severe, life-threatening allergic reaction that requires immediate emergency medical attention.